1. Field of the Invention
The invention relates to a control system for a vehicle, which is configured to change the running characteristic of the vehicle.
2. Description of Related Art
The behavior of a vehicle, such as a vehicle speed and a running direction, varies depending on a driver's accelerating/decelerating operation or a driver's steering operation. The correlation between the operation amount and a variation in the behavior is determined not only on the basis of energy efficiency, such as a fuel consumption, but also on the basis of various characteristics, such as ride comfort, quietness and power performance required of the vehicle. Such a so-called running characteristic is set on the basis of a vehicle type, or the like, and is, for example, set by appropriately adjusting the characteristic of an engine output torque and gear shift against a driver's accelerator operation, the characteristic of braking force against a driver's brake operation, the characteristic of a steering mechanism against a driver's steering operation, the damping force characteristic of a shock absorber of a suspension mechanism, or the like.
The running characteristic set on the basis of a vehicle type, or the like, as described above is absolutely set so as to satisfy an assumed design condition. In contrast, there are various running environments in which vehicles run, such as urban areas, expressways, ascending roads and descending roads. In addition, there are various so-called driving orientations, such as preferences and tastes, in actual driver's driving, and a driving orientation may vary for each running environment. Therefore, in fact, the characteristic required of a vehicle varies for each driver or each running environment. Thus, in order to set the running characteristic of a vehicle, which exactly incorporates a driver's driving orientation, there is a need for bringing the driver's driving orientation into coincidence with the running characteristic of the vehicle as much as possible.
On the other hand, for example, there has been developed a technique that controls and outputs a sound effect, a display image, a pressure, vibrations, or the like, that acts on human's sense of sight, sense of hearing, sense of touch, or the like, to apply a stimulus on the basis of the running condition of the vehicle, such as the speed or acceleration of the vehicle and the output torque of the engine during running. An example of this configuration is described in Japanese Patent Application Publication No. 2008-25492 (JP-A-2008-25492). A vehicle control system described in JP-A-2008-25492 is configured so that a driver's operation amount by which operating means is operated at the time of generating an acceleration is detected, a transitional operation amount and an operating speed from a steady state of the operating means is computed on the basis of the operation amount, at least one of a target acceleration and a target sound pressure that increases by the amount of increase that exceeds a discrimination threshold for each period of time that a human is able to feel a received stimulus is computed on the basis of those computed transitional operation amount and operating speed and then at least one of a torque generating device that generate driving torque and an in-vehicle audio device that outputs engine sound is controlled on the basis of the at least one of the computed target acceleration and target sound pressure.
In addition, Japanese Patent Application Publication No. 2008-176851 (JP-A-2008-176851) describes a vehicle sound effect generating device that generates a sound effect on the basis of sound source information formed of information about the running condition of a vehicle or the operating state of an engine. The device described in JP-A-2008-176851 is configured so that a control signal for generating a sound effect is generated on the basis of the sound source information and is output as a sound effect, a running environment signal that indicates the running environment of the vehicle is generated and the output characteristic of the control signal is varied on the basis of the running environment signal. In addition, JP-A-2008-176851 particularly describes the device that is configured to vary the output characteristic of a control signal for generating a sound effect on the basis of the acceleration of the vehicle.
In addition, Japanese Patent Application Publication No. 2007-256841 (JP-A-2007-256841) describes an in-vehicle acceleration display device that is configured so that the acceleration of a vehicle is detected to output an acceleration detection signal, a display control signal for graphically displaying the acceleration of the vehicle in a mode based on its variation on the basis of the acceleration detection signal is output and then the acceleration of the vehicle is graphically displayed on the basis of the display control signal.
Then, Japanese Patent Application Publication No. 2006-188132 (JP-A-2006-188132) describes a driving information transmitting device that transmits information about the accelerating/decelerating state of a vehicle to a driver through the sense of touch. The driving information transmitting device includes means for applying a first pressure stimulus to at least part of the area from the back to the buttocks of a driver's body seated on a driver seat from the vehicle rear side to the front side and means for applying a second pressure stimulus to at least part of the thighs of the driver's body seated on the driver seat from the lower side to the upper side. The driving information transmitting device is configured to apply the first pressure stimulus to the driver when the acceleration of the vehicle is detected, and to apply the second pressure stimulus to the driver when the deceleration of the vehicle is detected.
Note that JP-A-2006-188132 describes a music selection and playing method that, for example, incorporates the condition of a host vehicle, the surrounding condition of the host vehicle and the condition of a passenger, such as a season, weather, weekday, the time of day, a vehicle speed and a destination, to score and rank a plurality of pieces of music data, and then the ranked music data are sequentially transmitted to an audio device in the descending order and are played.
The above descried publications, for example, describe the audio device that generates engine sound or a sound effect, the display device that graphically displays a variation in acceleration or a pressurizing/vibrating device that generates a pressure or vibrations for applying a stimulus to a driver are controlled on the basis of the acceleration (or deceleration) of the vehicle. In other words, the above descried publications describe that a so-called effect producing device that outputs a so-called produced effect, such as sound, light, image, pressure and vibrations, which applies a stimulus to a human's sense, such as the sense of hearing, the sense of sight and the sense of touch, is controlled on the basis of the acceleration of the vehicle.
Here, the acceleration of a vehicle varies in response to a driver's driving operation, such as an accelerator operation, a brake operation and a steering operation, and, in addition, such a driver's driving operation is conducted because of various factors. Furthermore, the acceleration of the vehicle may occur or the acceleration of the vehicle may vary depending on a road condition, a running environment, or the like, on which the vehicle runs. That is, the acceleration of the vehicle occurs or varies depending on various factors or conditions.
Thus, as in the case of the devices described in these publications, when the above described so-called effect producing device is controlled simply on the basis of the acceleration of a vehicle, there is still room for improvement in order to bring the produced effect output by the effect producing device into coincidence with the image or taste of the driver, that is, in order to execute control by appropriately incorporating a driver's driving orientation into the details output from the above effect producing device. In addition, similarly, when the above described running characteristic of the vehicle, such as a power characteristic, a steering characteristic and a suspension characteristic, is adapted to a driver's driving orientation as well, there is still room for improvement.